Machine for flanging tubular members



Feb. 26, 1963 F. J. FUCHS, JR.. ETAL 3,

' MACHINE FOR FLANGING TUBULAR MEMBERS Filed May 2'7, 1960 6 Sheets-Sheet 1 JNVENTORS FJ. FUCHS JR H R. T/LLMAN 4 Feb. 26, 1963 F. J. FUCHS, JR.. ETAL 3,

MACHINE FOR FLANGING TUBULAR MEMBERS F. J. FUCHS, JR., ETAL Feb. 25, 1963 Filed May 27, 1960 Feb. 26, 1963 F. J. FUCHS, JR., ETAL MACHINE FOR FLANGING TUBULAR MEMBERS 6 Sheets-Sheet 4 Filed May 27, 1960 INVENTORS F J. F UCHS JR. H R. TlLLMAN ATTORNEY Feb. 26, 1963 F. J. FUCHS, JR.. ETAL 3,078,906

' MACHINE FOR FLANGING TUBULAR MEMBERS Filed May 27, 1960 e Sheets- Sheet 5 0: $2 Q g v 2+ 8 INVENTORS t2" 1w FUCHS JR t H R. T/LLMAN Q Feb. 26, 1963 F. J. FUCHS, JR.. ETAL' MACHINE FOR FLANGING TUBULAR MEMBERS Filed May 27, 1960 6 Sheets-Sheet 6 psa v V 28 2/ 4 \zaa I INVENTORS FJ FUCHS JR. BY H R. T/LLMA/V lzweeu.

ATTORNEY United States Patent 34978906 MACHINE FOR FLANGENG TUBULAR MEMBERS Francis J. Fuchs, in, and Henry R. Tillman, Winston- Salem, N.., assignors to Western Electric (Jompany, gicoggporated, New York, N.iZ., a corporation of New Filed May 27, 1960, Ser. No. 32,353 14 Claims. (Cl. 15330.5)

The invention relates to a machine for flanging tubular members and more particularly to an indexable flanging machine for successively and progressively upsetting an end of a wave guide.

The successful use of wave guides for transmission of microwave energy is dependent to a great extent upon the use of wave guide sections manufactured within tolerances which closely approximate the theoretically ideal Wave guide.

The utilization of wave guides in a system necessitates the connection of a great number of Wave guide sections for construction of transmission towers or lines, the replacement of defective sections, and the insertion of auxiliary equipment for transmission control at various locations. Additionally, as the wave guide lines may be filled with a gas such as nitrogen to protect the interior from corrosion, or to minimize breakdowns at high voltages, it is necessary to have a sealed joint, and for electrical reasons, the joint must mate nearly perfectly around the inner perimeter of the tubing to prevent electrical distortion.

it has been the practice in the past to utilize tubular Wave guide members to which a flange was brazed, but this resulted in an annealing and loss of strength plus a certain amount of distortion due to warpage from the brazing heat. Also, it was found that since the cross-section of a Wave guide is a critical dimension, the excess material deposits and warpage resulting from brazing required time-consuming filing and sizing before the wave guide sections could be successfully assembled. Also, in instances where threads were provided to join sections, it was found that the threads weakened the tube, and further that it is very expensive to form threads of the required precision.

The present invention overcomes the difficulties of wave guide manufacture by utilizing a cold flanging process to form a flange on a wave guide section.

'It is the object of the present invention to provide an improved and new apparatus for placing a flange on a tubular member.

Another object of the invention is to provide an automatic, hydraulically-operated apparatus for successively and progressively upsetting an end of a tubular member to produce a stronger, more uniform flange on the tubular member.

It is a further object of the invention to provide an automatic flanging apparatus which utilizes an indexable punch head which facilitates the use of a plurality of punches for progressively upsetting the end of a tubular work piece in distinct stages to produce a stronger more uniform flange on the member.

It is another object of the invention to provide apparatus utilizing an indexable die plate which successively positions dies to facilitate the progressive upsetting of the end of a tubular work piece to place a flange thereon.

It is a further object of this invention to provide an electrically controlled, hydraulically operated, automatic flanging machine utilizing indexable punches and dies for progressively placing a flange on a tubular member in distinct stages.

A machine embodying certain aspects of this invention may include a workpiece gripping assembly, a die indexing assembly, a punch indexing assembly, ram assembly and a control system. A work piece is held in a work position between stationary and movable clamp elements of the gripping assembly. Cam surfaces on a pair of cam bars engage cam followers on a die plate having dies mounted therein. The cam bars carry the die plate and dies to position a first of the dies over one end of the work piece so that the positioned die can receive a punch to upset the end of the workpiece. A punch on a rotary punch holder is inserted within and withdrawn from the positioned die by the ram assembly. Withdrawal of the punch actuates a switch in a control system to begin rotation of the rotary punch holder which in turn closes another switch to begin operation of the die indexing assembly. A second die is positioned over the Work piece, a subsequent punch is rotated into alignment with the work piece and die, and the machine is then ready to begin another punching operation.

Other objects and advantages of the invention will become apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a flanging machine embodying the principles of the present invention, wherein a portion is cutout to disclose various working components therein;

FIG. 2 is a partially cut-away side view showing an indexable punch, ram head, and ram toggle assembly together with appropriate connections to the chassis of the machine;

FIG. 3 is a fragmentary view, partially in section, of the machine shown in FIG. 1 disclosing the clamp toggle and jaws, a clamp stop cylinder assembly and a work piece positioned within the die plate between the clamp aws;

FIG. 4 is a sectional view taken along line 4-4- of FIG. 3 disclosing the face of the die plate together with a pair of cam bars and die indexing cylinders;

FIG. 5 is a front view of one of the cam bars showing various cam surfaces which engage a die plate cam fol: lower to index a die plate plus a guide channel for a clamp jaw;

FIG. 6 shows a front view of the punch holder disclosing four punch positions and a punch holder indexing gear;

FIG. 7 is a fragmentary view showing the face of the die plate together with one of the cam bars;

FIG. 8 is a sectional view taken along line 8--8 of FIG. 4 showing the die plate, gripping jaws and positioned workpiece;

FIG. 9 is a schematic of a hydraulic system in conjunction with electrical control elements for operating the flanging machine;

FIG. 10 is an electrical circuit utilized to control the operation of the flanging machine shown in the other views; and

FIG. 11 is a mechanical schematic diagram illustrating the physical relationship between various microswitches, cam surfaces, and principal machine elements.

Referring now to FIG. 1, the flanging machine comprises a box-like chassis 21 for containing the various elements of the machine. Pedestal-like projections 22 of the chassis are adapted to mount the machine on a suitable foundation. A yoke 23 is securely attached to the chassis and acts as a mount upon which additional elements are mounted.

A work clamp including clamp jaws designated by the numbers 24 and 25, see FIGS. 1 and 3, is adapted to grip a work piece such as a tubular member 32 and restrain the member against horizontal and vertical movement during a subsequent flanging operation. The staapropos tionary jaw 24 of the work clamp is secured to the yoke 23. The movable jaw 25 of the clamp is attached to a clamp toggle 26 and is guided in vertical straight channels or guideway 49 formed in cam bars 27, see FIG. 5. The clamp toggle 26 is operated by a hydraulic cylinder and piston '28 which is pivotally secured to the machine chassis by trunnion's 29. A clamp toggle stop in the form ofa second hydraulic cylinder and piston 31 is secured to the housing 30 of the clamp cylinder 28 and is positioned to oppose the clamping motion of clamp piston 2821. As the clamp toggle cylinder and piston 2 8 begins to move the clamp toggle 26 in the clamping stoke, the movable clamp element 25 is forced upwardly in a vertical'plane to engage the tubular workpiece 32 and force the work piece against the stationary clamp jaw 24.

In order to selectively align dies 53 and 54 with work piece 32, cam surfaces on two cam bars 27 are forced into engagement with a die plate .35 by indexing pistons and cylinders 33. In a first of two work positions, "as

disclosed in FIGS; 1 and 4; pistons 33a force cam bars 27 upwardly to hold the die plate 35 in an uppermost position and to align die 54 with work piece 32. After preliminary upsetting of workpiece 32 has been completed, utilizing die 54, die 53 is moved into alignment with the work piece. "Pistons 33a are operated to pull cam bars '27 downwardly in the vertical plane. Cam surfaces 62 of cam bars 27 engage'cam followers 34- on the die plate 35 to facilitate downward movement of die plate 35, consequently, die 53 is moved into alignment was work piece 32. e

L .hydranlic cylinderiio is pivotally attached to the machine chassis 21 by trunnions' 37. Cylinder and piston 36 operate a ram toggle 38 which through the agency f 42 moves a ram head 39 and a punch holder 41. After workpiece 32 is gripped by clamp 25, with die plate 35poisitioned to align die 54 with the work piece, the hydraulic piston 36a operates the ram toggle and the ram. head 39 toforce a punch 43 into working engagement with the work piece 32. After the punching operation is completed, the piston 36a is: reversed and the ram head 39 is returned to an unoperatiyeposition illustrated in 1. Reversal of the ramhead 39 results in closure of switch L812 which initiates indexing of aro'tja'rypun'ch holder '41 to bring a subsequent punch into alignment with the workpiece 32. Indexing of punch holder 41 initiates the operation ofthe die plate indexing assembly and die 53 is aligned with work piece 32 in preparation -for subsequent punching operations. u

Following is a'more detailed description of the various units of the vhanging machine. i p v clamping assembly of the flanging machine is best illustrated in FIG. 3. Stationary clamp jaw 24 is attached to fixed yoke 23. of the machine and is provided with a gripping surface that is shaped and suitably grooved to accept and secure the work piece 32 against movement. Guide pins 44 are rigidly attachedto the stationary clamp jaw and are adapted to ride within guide apertures 45 formed in the die plate 35, see FIG. 8. These guide pins 44 insure that the die plate 35 is correctly positioned with respect to the work piece 32. Theclarnp piston and cylinder 28 is attached to and operates the clamp toggle 26. A link 46 of the toggle 26 is pivotally connected to the machine chassis by a pivot shaft 47. A link'48 of the clamp toggle 26 is pivotally connected to the movable clamp jaw 25. When fluid is forced into clamp cylinder 28 during the operating phase of the machine, the piston 28a will force the toggle links 46 and 48 to the right of the position shown in FIG. 3. Inasmuch as pivot shaft 47 is fixed, the toggle links 46 and 47 will move toward 'astraight line position to force clamp jaw in the vertical direction. Clamp 'jaw 25 isguided in the vertical direction by channels49, see FIG. 5, formed in cambars 27 Upward vertical movement of clamp jaw. 25. forces the, gripping surface 51 of the clamp jaw 25 into engagement with the work piece '32 whereafter 4 the work piece is forced against the stationary jaw 24, thus securing the workpiece 32 against movement.

In a preferred embodiment of the machine, the clamping operation takes place in two distinct steps. First, there is a clamping motion which secures the work piece between the clamp jaws 24 and 25 under a slight amount of pressure and, secondly, there is the phase duringwhich the workpiece 32 is clamped with a greater pressure. This two-phase clamping is desirable in a case where the final clamping pressure necessary to secure the work piece for a particular type of punching operation is so great that it may crush the sides of a tubular work piece. In order to prevent collapse of the walls of a tubular work piece, insertion of amandrel into the workpiece to support the walls is necessary. Insertion of the mandrel is efficiently accomplished if thework pieceis first secured against movement byaslight clamping pressure. After the mandrel has been inserted to support the walls of the-work piece, the final clamping pressure necessary to secure the work piece. for thepunchihg operation can be applied with no resulting damage to the walls. of th e workpiece. order to ac complish theabove objective, thefclamp toggle "stop cylinder and piston 31 is provided to oppose the operating motion of the clarnp piston 284. During the time that fluid is being forced into clamp cylinder 2810 operate, the clamp toggle 26 in th'eclamping phase, fluid is also being forced ipto stop cylinder 3 1 The force. exerted by the clamp piston 28:; overcomes the opposing forcefof the stop cylinder and piston 31 until a'predeterniinedclamping pressure is exerted on the work piece. When this predetermined clamping pressure has beenbuilt upto oppose the action of the clamp piston 2821', the stop cylinder and piston 31 will be momentarily effective to stop fur ther motion of the clamp jaw 25 by clamp piston 28a. Duringfthe momentary stop, a mandrel 52, see FIG. 2, is inserted into the work piece 32., After the tnornent'aryfSwp and in response to closure of 'switch L510, solenoid S63, "see FIG. 9,. is energized and a presshreredu'ccr and stop cylinder 31 are simultaneously switched out of the hydrauliccircnit. Closure of LSIQ also completes a circuit for solenoid S 7B whic h functions to shift valve S7 to connect a pressure responsive sequence valve 99in the hyd'raulic system. The sequence valve 99 controls the application of highpressure "to the clamp cylinder 28 and the index cylinders 33. The clamp piston 28a and toggle 26 will then force jaw 25. into final clamping engagement with th e work p eces: which time the punching operation is ready to be carried out on the work piece The machine performsseveral hanging and punching operations on the work piece in order to accomplish these operations'the die plate 35 containing two clifierent dies 53 -and.54,, see, FIG. 7, is indexed to one of two positions. The dies 53 and 54am selectively carried into alignment with the work piece 32 through the "cooperation of die plate 35, cam bars 27 and indexing cylinders and pistons 33.

fIhe indexingcylinders33 are rigidly fastened to the chassis 21 and the. pistons 33a are connected to two cam bars 27 as disclosed in FIGS. 1 and 4. These figures show the cam bars 27and the die plate 35 in the first indexed position so that die 54 is in position over a work piece 32. The cam bars 27 are guided to move in the vertical plane by dove tail grooves formed in the chassis which receive dov e tails 55 fo rrned on the cam bars 27.

'Ihe die plate 35 is mounted between the parallel cam bars 27 and cam followers 34 on the edge of the die plate 35 fit within camchannels 57 formed in the cam bars 27. The rear surface 56 of the die plate 35 rests against the front surfaces of yoke 23 and clamp jaws 24 and 25 of the machine. 1 'Ihefcarn followers 34 and the cam channels 57 of cam bars 27 cooperatively secure the die plate 35 against horizontal movement while the die plate 35 is in anoperation position against the yoke 23 and the clamp jaws 24 and 25. The die plate 35 is $8- cured against vertical movement in the first indexed posi-- tion by guide pins 44 and an upper die plate stop 58. The guide pins 44 which are rigidly attached to the stationary clamp jaw 24 fit within the guide pin apertures 45 of the die plate 35 to prevent the die plate from moving vertically downward while die 54 is aligned with the work piece. The upper die plate stop 58 limits the vertical movement of the die plate in the upward direction.

Refer now to FIG. 1 generally and particularly to FIG. 5, after a first punching operation has been completed by the machine with the die plate 35 and cam bars 27 in the first indexed position (as shown), the indexing pistons 33a are actuated to pull the cam bars 27 vertically downward. Prior to any downward vertical movement of the cam bars, the cam followers 34 which are part of the die plate 35, see FIG. 7, are engaged with surfaces 59 and 61 of cam channel 57. In this position, the cam followers 34 are restrained by surfaces 59 and 61 of the cam channel 57 from horizontal move ment to the left in FIGS. 3 and 5, and since the rear surface 56 of the die plate 35 is resting against the yoke 23, the die plate 35 is locked in the horizontal plane. As indexing cylinders 33 begin to draw the cam bars 27 vertically downward, guide pins 44 restrain the die plate 35 from moving downward so that the cam bars 27 move vertically downward relative to the die plate 35. The cam bars 27 move downward with respect to the die plate 35 until cam followers 34 engage surfaces 62 of the cam channel 57. Continued downward movement of the cam bars 27 results in the cam followers 34 following surfaces 62 thus imparting horizontal movement to the left to the die plate 35 in FIG. 3. When the cam followers 34 reach point 63 in the cam channel 57, the die plate 35 has been moved horizontally away from the clamp jaw 24 a sufficient distance so that the guide pins 44 have been disengaged from the guide pin apertures 45. The guide pins 44 now no longer restrain the die plate 35 from downward vertical movement.

At the same time that the cam followers 34 are cammed to position 63 in the cam channel 57, the cam bars have moved relative to the die plate 35 far enough so that spring loaded detents 64 on either side of the die plate, see FIG. 7, engage detent channels 65 formed in the cam bars 27. The channels 65 are formed with bevelled sides.

With the detents 64 engaged to carry the die plate with the cam bars 27, with the cam followers 34 in position 63, and with the guide pins 44 disengaged from the die plate 35, continued downward movement of he cam bars 27 will carry the die plate vertically downward until further downward movement of the die plate 35 is arrested by lower die plate stop 66. Stoppage of the die plate by the lower stop 66 again results in relative vertical movement of the die plate 35 with respect to the cam bars 27. The spring loaded detents 64 are cammed out of detent channels 65 and the cam followers 34 are forced to engage surfaces 67 of the cam channel 57. As the cam followers 34 travel along surfaces 67, the die plate is forced to move horizontally to the right as viewed in FTGS. 3 and 5 into contact with the clamp jaws 24 and 25. The disengaged guide pins 44 reengage a second set of guide apertures 68 in die plate 35. These guide apertures 68 cooperate with guide pins 44 to restrain the die plate 35 from vertical upward movement and also accurately position the die 53 in alignment with 'work piece 32. Continued downward movement of the cam bars continues until the cam followers 34 are locked behind surface 69 of the cam channel 57. After the die plate 35 is locked to secure it from horizontal movement, tthe indexing pistons 33a discontinue movement. The die plate 35 and die 53 are now in the second indexed position and ready for the subsequent punching and Hanging operations to begin. It should be understood that although the operation of the cam bars 27, die plate 35 and index cylinders 33 was described as the 6 can bars 27 were forced vertically downward from a first indexed position, as disclosed in FIG. 1, the indexing of the die plate 35 can take place in reverse. Reverse operation of the cam bars 27 results in movement of the die plate 35 exactly in reverse of that above-de scribed and therefore, will not be described in detail.

The ram head 39 is attached to toggle link 42, as illustrated in FIG. 2. This ram head carries the punch holder 41 on which four punches are mounted 90 apart. Only one of these four punches is in operation at any one time. When a given punch is to be used, it is indexed to the uppermost of four possible head indexing positions such as illustrated by punch 43, of FIG. 2. The punches are indexed to work position by a fluid m0- tor 73, which mechanically drives spur gear 71, see FIG. 6. Gear 71 meshes with ring gear 72 on the periphery of the punch holder and drives the punch holder 41 in the counter-clockwise direction. The indexing of the punch holder takes place in response to the hydraulical ly operated fluid motor 73 under the control of an electrical control circuit illustrated by FIG. 10.

Cam 77 having peripheral cam surfaces 74, 75, and face cams 76 is adapted to operate suitable microswitches LS7, LS6, and LS8, respectively, as illustrated in FIG. 11. Cam surface 74 strikes switch LS7 at the end of a complete operating cycle of the machine in order to initiate stoppage of the machine. Face cams 76 disengage switch LS8 so that the indexing of the punch holder can be stopped at the proper succeeding work position. While the punch holder 41 is in the position illustrated in FIGS. 6 and 11, the cam surface 75 is not engaging switch LS6 and switch LS6 is open, see FIG. 10. Since LS6 is open, solenoid 81A is energized through switch LS4 and normally closed contact A4 and, therefore, fluid is forced into cylinder 33 to maintain die plate 35 in the uppermost position,

illustrated in FIG. 1. When the punch holder 41 rotates to the second work position, switch LS6 is operated by earn surface 75 of the cam 77 on the punch holder 41 and the die plate 35 in response to the closure of switch LS6 is indexed to the second work position. Springs '78, see FIG. 6, act as inertia take-up devices. Each spring 78 is contained within a recess 111 formed in the rear surface of punch holder 41. Each lug 109, which is a part of a rim 112 of cam 77 engages and compresses each spring 78. As the holder is being rotated by fluid motor 73, the dynamic inertia of the rotating holder 41 prevents stoppage at an exact predetermined position and results in overriding the work position. When the fluid motor 73 stops rotation of the holder 41, the springs 78 are compressed by lugs 169 to absorb overtravel of the hydraulic motor 73. The cams 76 are actually depressions formed in the face of the holder 41. A spring urged detent 75a engages the face of the holder 41 so that when the motor 73 stops, the detent 75a moves within a cam depression 76 to hold the punch holder in a predetermined work position.

In one embodiment of the machine, the four punches are hollow and each contain a mandrel 52. Since a great deal of pressure is applied to the walls of a tubular workpiece 32 by clamp jaw 25, there is a possibility that the sidewalls of the work piece may collapse. To prevent collapse of the sidewalls, the mandrel 52 is inserted into the tubular work piece prior to the time the final clamping pressure is applied by the clamp jaw 25.

The head 39 and punch holder 41 are pivotally attached to toggle link 42 by a pin 79. As the piston 36a moves the link 42 downwardly, the ram head 39 is moved in the horizontal direction out of engagement with the work piece 32 and die 54. The head is restrained in the horizontal plane by suitable guideways 81 which are mounted on the machine chassis 21.

Link 82 of the ram toggle is connected to the machine chassis 21 by block 83 which is bolted to the chassis 21. The bolts are not shown. Between the chassis wall 84 and the block 83 is a pressure responsive device 85 t 7 r utilized to operate certain controls in the machine. The pressure responsivedevice 85 is a hollow metal body in the form of a parallelepiped which actuates pressure responsive switches PS1, PS2, and PS3, see FIG. 11, and is filled with oil or some other suitable fluid medium under a predetermined pressure. The fluid in the pressure responsiv'e device 85 communicates with and operates Bourdon tubes 121, 122, and 123 to operate pressure respo usive switches PS1, PS2, and .PS3 respectively. A niajor wall of the pressure device 85 which rgsts against block 83 is as large as and matches the surface v113 of block 83 so tha t as block 83 is forced to the left in FIG. 2, forces transmitted through block 83 compress the periphery of minor walls of device 85 between block '83 and chassis Wall 84. Since the minor Walls which form the periphery of the pressure device 85 are compressed by the forces exerted when rain assembly 38 operates, the major walls of the pressure device 85 will bemoved together relative to each otherbetweenchassis wall 84 and block surface 113, thus compressing the fluid within the pressure device 85. A change of the predetermined pressure within the device 85 is sensed by the pressure sensitive switches PS1, PS2, andPS3. The forces exerted on the periphery of the pressure device 85 when ram assembly 38 operates are not large enough to exceed the elastic limit of the materialin the minor walls, but adequate coinpression takes place to effectuate an appreciable change in fiuidpres'sure. ,7

One embodiment of the present machine contemplates the, use of two different punching pressures for the first punching operation and a second toggle pressure for the subsequent punching operations. To accomplish these difi erent punching pressure requirements, a low pressure responsive switch PS I is placed in the pressure device 85, seeFIGS, land 11. On the first punching operation the pressure exerted on the ram head 39 by toggle 38 will be sensedby pressure sensitive switch PS1 when the predeterrniried pressure of the pressure device 85 has been changed by a given value. Switch PS1 will, by controlling the. hydraulic circuit, limit the toggle pressure for the first punching operation. Since higher punching pressures are desired for the subsequent punching operations, a second pressure sensitive'switch PS2 is placed in the pressure device 85. After the first punching operation, switch PS2 rakes 'oyer control 'of thehy'draulic system and the ram toggle 38 exerts a great deal more pressure on the ram head 39 and, consequently, on the'pressure device 85 before pressure switch PS2 closes and reverses the ram head39 i i i Also, included in the pressure device 85 is a third pressure sensitive switch PS3. This switch is operated to stop the rnachine in the event that the preload pressure in the device 85 falls below a predetermined value. I

A complete description of the operation of the machine will now be given to include the electrical circuit of FIG.

It), the mechanical, schematic of FIG. 11 and the hydraulic schematic of FIG. 9.

Refer first to the electrical circuit, 10.. Power source 36 provides power to operate the hydraulic pump motor 87 ,to apply pressure to the fluid in the hydraulic system of FIG. 9, and also, it provides the power for the electrical control system which is illustrated by the cireuitry of FIG. 10, and which is fed by transformer 88.

N First the power source 86 energizes the hydraulic pump motor 87. At this time the power unit 91 (see FIG. 9) of the hydraulic system builds up fluid pressure in the hydraulic system in preparation for operation. Next, switch 92 is manually closed to setthe, electric control circuit for automatic operation, the cold fianging machine can also be readily adapted to operate with a manual push-button type electrical control circuit. Pressure operated safety switch PS3 is normally closed and remains so th u ho t the ma ine. at n n e t P a :pressure in device 8 5 fallsbelow apredeterrnined level.

In the event the pressure fails to build up in the hydraulic 8 system, the switch PS3 will operate and the machine will be turned 'ofi.

Next the manual push-button switch PB4 is closed. Since switch LS2 is normally closed at the beginning of the cycle due to engagement with a cam surface on toggle link 195 when the clamp 25 completely released the work piece at the end of a previous cycle, closure of switch P34 completes an electrical eireuit through a solenoid SSA. Energized solenoid SSA operates hydraulic valve S5 to allow oil to how into pressure line 93 which is necessary to operate the machine. Solenoid SSA rei'nains energized throughout the operating cycle of the machine.

Manual closure ofa switch PB4 completes an electrical circuit throughsolenoid S2A. Solenoid S2A operates hydraulic valve S2 to place pressure on line 94. When line S t is pressurized, oil is forced through a pressure 'rcducer into clamp toggle cylinder 28. Piston 28a begins toforce clamp toggle 26 in the operating phase so that clamp jaw 25 armed in the upward direction to engage the work piece 32, which is inserted between the stationary clamp jaw 24 and the movable clamp jaw 25. Since pressure reducer 25 is in the hydraulic system, the hydraulic pressure which builds up in clamp toggle cylinder 2-8 is limited to a predetermined value such 'as 200 psi.

At the sametime that hydraulic pressure is building upin clamp toggle cylinder 23, hydraulic pressure is also bilding up in clamp toggle stop cylinder 31. Fluid under pressure in line 94 is forced through line 106 to yalve S6 and into the stop cylinder 31 through line 104. When the clamp cylinder has moved the clamp toggle links 46 and 4-8 far enough so that work piece 32 is securely clamped, the links 46 and 48 will come to rest against the piston or stop cylinder 31. Since the clamp cylinder 28 is being actuated under a reducedpressure of 200 12.51., and since the stop cylinder 31 is at hne pressure, the force of the clamp cylinder will be overcome by the opposing force of the piston of stop cylinder 31 and further clamping force will be momentarily stopped.

Nextmanual push-button switch PB7 is closed, Closure of switch P137 completes an electrical circuit through relay CR1 which closes contacts CR2, CR3, CR4, CR5, CR6, and CR7. Closure of switch PB7 also completesan electrical circuit through solenoid S1A. Solenoid Sl-A actuates hydraulic valve S1 to alow oil to flow in line 96 to the flow divider 97 and into indexing cylinders 33. Indexing pistons 3311 move the die plate 35 in the upward direction to place die plate 35 in the first operating position as disclosed in FIG. 1. In this position, die 54 is in position to cooperate with the first of four punches on the punch holder 4-1. As the indexing pistons 33a move the die plate into the first operating position, a cam surface on die plate 35 shown in FIG. 11, strikes and closes switch LS4. Closure of switch LS4 completes a circuit through solenoid 81A and maintains the indexed die plate 35 in the upward or first operating position. Switch LS1 located adjacent to toggle link and operated by a cam surface on the link 105, see FIG. 11, is closed by the initial forward movement of the clamp toggle 26. Switch LS1 augments the operation of switch ?B7 and locks the control circuit into an automatic cycle by maintaining relay CR1 closed after switch PB7 is released.

As the above switches are being closed, the effect of the clamping cylinder 28 has been completely overcome by the piston of clamp stop cylinder 31. At the completion of the initial clamping motion, a switch LS3 is closed by the forward motion of the clamp toggle, see 11. Since switch LS9 is normally closed at the beginning of the operation, closure of switch LS3 will complete an electrical circuit through time delay relay C which immediately closes contact C1 and "completes a circuit through solenoid 8313. The energized solenoid SSBoperates hydraulic valve S3 which allows oilto flow into line 98 and into the ram cylinder 36. This'oil flow to cylinder 35 results inoperation of'the ram toggle 38 which in turn forces the ram head 39 to travel toward the clamped work piece 32. Mandrel 52 is inserted within the work piece 32 during the initial movement of ram head 39 while the workpiece 32 is being secured by a slight clamping pressure. After a time delay as determined by relay C, contact Cl. is opened and solenoid 53B is deenergized but since valve S3 is not spring biased to return the valve to a previous position, the hydraulic valve S3 remains in the operated position, such that fluid continues to enter ram cylinder 36 through line 98.

As the ram head 39 moves forward, a lobe cam, shown only in FIG. 11, on chassis 21 actuates and closes switch LSlltP. Closure of switch LSltl completes an electrical circuit through solenoids 86B and S7B simultaneously. Energized solenoid S7B places a 1500 p.s.i. sequence valve 99 into the pressure line 98 of the ram hydraulic circuit. Sequence valve 99 impedes the flow of fluid to cylinder 36 until a predetermined pressure, such as 1500 p.s.i. is attained in the pressure line 93, thus advance of ram head 39 is momentarily interrupted.

Energized solenoid Sd-B operates hydraulic valve S6 to switch the pressure reducer 95 and the clamp toggle stop cylinder 31 out of the hydraulic circuit. When valve S6 is operated, fluid drains out of cylinder 31, through line 1%, and into drain 107 through valve S5. Actuated valve S places line pressure on reducer 95 through line 166 to force reducer 95' out of operation. Now while the mandrel S2 is supporting the walls of the work piece 32 and the pressure sequence valve 99 is maintaining the ram 39 motionless, the pressure in line 94 of the clamp cylinder 28 builds up to overcome the deactivated clamp stop cylinder 31 and to force clamp jaw 25 to secure work piece 32 in the final clamping phase in preparation for the punching operation.

After pressure in the ram hydraulic circuit operates the pressure sequence valve 99, oil under full line pressure is forced through line 93 and into ram cylinder 36 to advance the ram head 39 and force the punch 43 into engagement with the exposed end of work piece 32 to upset the end thereof.

Punching pressure is applied to the work piece 32. by the ram toggle assembly 33 until a predetermined magnitude of pressure is attained. When this given magnitude of pressure is attained by the ram toggle assembly 38, the force of the ram toggle 38 against the machine chassis at surface 84 will compress the Walls of pressure sensitive device 85. The changed fluid pressure in the pressure sensitive device 85 will operate pressure sensitive switch PS1.

Closure of pressure sensitive switch PS1 completes the electrical circuit through time delay relay E and results in closure of contact E1. Closure of contact E1 results in energization of solenoid 53A. Energized solenoid SSA operates hydraulic valve S3 and reverses the fluid flow to the ram cylinder 3.6. Fluid will now flow out through line 33 and fluid will be forced into line Mi l to reverse the ram cylinder 35. Reversal of the ram cylinder 3% thus results in releasing ram toggle 33 which in turn begins to back the ram head 39 and punch 43 away from the die plate 35 and the work piece 32.

The reversing ram head 39 results in disengagement of switch LSltl. When this occurs, solenoid S7B is deenergized and pressure sequence valve 99 is taken out of line 98. Thus, the pressure exerted by the ram head 39 and punch 43 on the Work piece 32 is released. Disengagement of switch LSld also results in deenergization of solenoid S63 and, consequently, pressure reducing valve 95 is placed back in the clamp cylinder hydraulic circuit. The pressure reducing valve 95 releases the clamping pressure on the workpiece very rapidly so that the work piece is secured by the clamp jaws at a reduced gripping pressure. The gripping pressure on the work piece is reduced before the mandrel 52 is extracted from the Work piece 32 by the reversing ram 39. The

work piece 32. is not entirely released by the clamp assembly until after all the punching operations have been completed, but merely relaxes the gripping pressure while the mandrel 52 is withdrawn from the work piece 32.. After each succeeding punching operation, the fluid pressure in cylinder 23 is reduced so that the work piece 32 will not be damaged by excessive clamping pressure. When switch LSltl is opened due to withdrawal of ram head 39, solenoid 86B is deenergized and valve S6 is returned to the position illustrated in FIG. 9 wherein fluid flows from line 1% into stop cylinder 31 and the pressure reducer 35 is operated to reduce the line pressure to cylinder 28. The piston 28a then reduces the gripping pressure on the work piece 32 until the advancing ram head 39 again inserts the mandrel within the tubular workpiece 32.

Continued reversing motion of the ram assembly will result in closure of switch L812, see FIG. 11. Switch L812 completes the electrical circuit through time delay relay D and also through solenoid S43. Since contact B1 is closed at this time and contact D1 will not be opened for a predetermined time, solenoid Sd-B operates valve S4, which actuates fluid motor 73 to begin indexing the punch holder 41. Fluid motor 73 which drives gear 72 through pinion '71 rotates the punch holder 41 in the counter-clockwise direction. After the time delay determined by relay D, contact D1 is opened to deenergize solenoid S415, but a machined surface between face cams 76 on the rotating punch holder 4-1 operates arm 192 and closed switch LS8 which maintains the electrical circuit through S t-B so that hydraulic valve S4- remains operative and the hydraulic motor 73 continues to rotate the punch holder at until the arm 19?, engages face cam '76, see PEG. 11, and opens switch LS8. When switch LS8 is opened solenoid S43 releases hydraulic valve S4 and the hydraulic motor '73 discontinues further rotation of the punch holder 41. Spring 78 of FIG. 6 is an inertia device adapted to correct any tendency the punch holder 41 may have to override the indexed position. After the punch holder 41 has come to rest, the second punch is in position for the next punching operation.

As the indexing head rotates to the second punch position, the disengaged switch LS6 is closed by surface 77. Closure of switch LS6 completes the electrical circuit through contact CR7 and relay A which closes contacts A1 and A3 and opens contacts A2 and A4 associated with switch LS4 and solenoid SlA. Solenoid 81B is energized and operates hydraulic valve S1 to reverse the fluid flow to indexing cylinders 33. Fluid now flows out of cylinders 33, through line 96, and into an exhaust line 1% through valve 51.

The indexing pistons 33a move downward drawing cam bars 27 downward, as previously described. As the cam bars travel downward, the cam followers 34 will follow cam channels 57 to first force the die plate 35 horizontally outward from the stationary jaw 24 to disengage guide pins 44. The die plate 35 will then be carried downward by the descending cam bars 27 until the further downward movement of the die plate 35 is arrested by die plate stop 66 at which time the die plate 35 will be cammed horizontally toward the clamp jaw 24 and guide pins 44 will move Within guide apertures 68. When the die plate 35 is in this second die plate position, such that die 53 is in alignment with work piece 32, the index pistons 33a will discontinue descent. The die plate 35 and die 53 will remain in this second die plate position and in alignment with the work piece for the remainder of the punching operations.

When switch LS6 is closed, and it remains closed for the remainder of the punching operations, contact A2 associated with pressure switch PS1 and solenoid SSA is opened and breaks the electrical circuit through solenoid SEA. Thus, solenoid SSA will not now afiect the operation of hydraulic valve S3.

Also during the indexing of the punch holder 41,

switchLS9 is opened; therefore, solenoid 53B is also deenergized and will not affect hydraulic valve S3. At -the end of the punch holder indexing when arm 102 enters a face cam 76 and opens switch LS8, switch LS9 is again closed. Since switch LS3 remains closed during the entire operation of the machine, closure of switch LS9 energizes solenoid $33 which operates hydraulic valve S3 to allow fluid flow in line 98 to begin forcing the ram assembly 38 in the forward direction to begin the second punching operation.

The subsequent punching operations take place exact- 19 as in the above-described operation except that on thesecond and subsequent punching operations, pressure switch PS2 takes control of the electrical circuit to reverse the ram 39 rather than pressure switch PS1.

At the end of the four punching operations, the punch holder will again be indexed so that the first punch is in position to begin another complete 'fianging'cycle. When this punch holder indexing takes place,'cam surface 74 on the punch holder 41, see HG. 11, strikes and closes switch LS7, see FIG. 10. Closure of switch LS7 comjilets the electrical circuit through solenoid 828 which in turn operates hydraulic valve S2. When valve S2 is operated by solenoid 8212-, it reverses the fluid how to clamp cylinder 28 so that the clamp toggle 26 completely withdraws clamp jaw "thus releasing the finished work "piece so that it can be removed from the machine. At this timethe machine is stopped and push-button switches P137 and P134 must again be closed to start the machine for another complete punching cycle.

It is who understood that the above-described arrang 'ment of apparatus and components and construction of elemental parts are simply illustrative 'of an application of the principles ofthe invention, and many other modifications may be made without departing from the invention.

What is claimed is:

1. In a "fabricating machine, a clamp, means for 'actuatingsaid clamp to grip a workpiece, means for opposing said actuating means, a fabricating'tool mounted for movement toward a workpiece gripped by said clamp,

means for moving said fabricating tool, and means'operated by the movement of said fabricating tool for rendering 'said opposing means ineffective.

2. In a fabricating machine, a clamp, means foractuating'said clamp to grip a workpiece,'means for opposing said actuating means, an index head having a plurality of fabricating tools mounted thereon, means for reciprocating one of said fabricating tools to advance and withdraw said fabricating tool from engagement with said workpiece, means operated by the'advance of said fabrieating tool for rendering said opposing means ineffective,

and means operated by the withdrawal of said fabricating tool for indexing said index head.

said opposing means ineffective, and means actuated. by "the withdrawal of said fabricating tool for operating said moving means to move said carrier to align a second of said dies with said workpiece.

4. A fabricating machine for upsetting the end of a tubular workpiece which comprises means for gripping "said workpiece, means for opposing the gripping means to li'mitthe gripping pressure exerted on said workpiece,

a die platehaving a. pair of dies mounted therein, means for selectively moving said die plate 'to sequentially position-said dies in operative association with a workpiece insaid gripping means, a fabricating tool, a'mandrel coaxially mounted with'said fabricatingtool, means for advancing said mandrel and -fabricating tool to insert said mandrel within said workpiece and to upset the workpiece within a first of said positioned dies, means operated by advance of said fabricating tool for deactivating saidopposing means after said mandrel 'has been inserted within the tubular workpiece, means responsive to a predetermined pressure exerted by said fabricating tool on said workpiece for withdrawing said tool from said first die, and means operated by the withdrawal of said fabricating tool from said first die for operating said selectively moving means to position the second die in operative association with the workpiece.

'5. In a fabricating machine, means for holding a workpiece, a carrier having a-pairof spaced dies mounted therein, means for selectively moving said carrier to sequentially position said dies in operative association with a workpiece insaid holder,-a fabricating tool, means for reciprocating said tool to advance said tool throughand from a first of said positioned dies to act on said workpiece, and means operated by the withdrawal of said fabricating tool from said first die for operating said selectively moving means to position the second of said dies in operative association with the workpiece.

6. In a fianging machine, means for holding a workpiece, a plurality of dies, die plate means for supporting the dies, a pair of cam bars having camming surfaces thereon, means for moving "said camming surfaces into engagement with said die plate means to selectively move said the plate means to sequentially position said dies into engagement with said workpiece, a punch holder having a plurality of punches mounted thereon, means for indexing said punches to a predetermined work position, means for reciprocating such positioned punch to advance said punch through andfrom a'first of said posi- 'tioned'dies to act on said held workpiece, and means operated by the indexing of a subsequent punch for operating saidmoving means to position the second of said dies into engagement with the workpiece in said holding means.

7. In a fabricating machine, means for holdinga work :piece, a die plate having a pair of dies mounted therein,

means for indexing said die plate to place a first of said dies into engagement with said workpiece in said holder, a fabricating tool, means for moving said fabricating tool through said first die and into and out of engagement with the held workpiece, means responsive to a predetermined force exerted on .said workpiece by said tool for interrupting further operationof said moving means, and means actuated by the withdrawal of said tool from said 'die by said moving means for indexing said die plate to place a second of said dies into engagement with said h'eld workpiece.

8. In a fabricating machine, a clamp, means for actuating said clamp to grip a workpiece, means for opposing said actuating means, a carrier having a pair of dies mounted therein, means for aligning said carrier and a first of said dies with said workpiece, a fabricating tool, 'means for moving said fabricating tool through said first die and into engagement with the gripped workpiece, means operated by the advance ofsaid fabricating tool by said moving means for rendering said opposing means .inoperative, means responsive to a predetermined force exerted on said workpiece by said fabricating tool for interrupting further operation of said moving means, and means actuated by withdrawal of said tool from said workpiece by said moving means for operating said aligning means to move said die plate to align a second of said dies with said workpiece.

9. A fla'nging machine for upsetting the end of a workpiece which comprises a clamp, means for actuating said clamp to grip said workpiece, means for opposing said actuating means, a die. plate having a pair of dies mounted therein, means for aligning said die plate and a first of said dies withsaid workpiece, a. punch holder having a plurality of punches mounted thereon, means for re ciprocating a first of said punches to and from engagement with said first aligned die and workpiece, means operated by advancement of said first punch to render said opposing means ineffective, means responsive to a predetermined force exerted on said workpiece by said first punch for interrupting further operation of said reciprocating means, means actuated by the withdrawal of said first punch from said first aligned die and workpiece for indexing said punch holder, and means actuated by said indexing means for operating said aligning means to move said die plate to align a second of said dies with said workpiece.

10. An indexing apparatus for moving a die int-o alignment with a workpiece which comprises a die plate hav ing a die mounted therein, a restraining means for engaging said die plate, cam bars having cam surfaces thereon for moving said die plate into and out of engagement with said restraining means, and means for moving said cam bars to cam said die plate out of engagement with said restraining means and to carry said die into alignment with said workpiece w-hereafter said cam bar moves said die plate to reengage said restraining means to secure said die in alignment with said workpiece.

11. In an indexing apparatus, a die plate having a die mounted therein, means for securing a workpiece, a restraining means for engaging said die plate with the die spaced from the workpiece, means for moving said die plate out of engagement with said restraining means and for aligning said die with said secured workpiece, and means on said moving means for reengaging said die plate with said restraining means to thereby secure said die in alignment with said workpiece.

12. In an indexing apparatus for moving a plurality of dies into engagement with a workpiece which comprises a die plate having a pair of dies mounted therein, cam followers secured to opposite surfaces of said die plate, a restraining means for restricting movement of said die plate to secure one of said dies in working engagement with said workpiece, a pair of cam bars having cam surfaces thereon for engaging said cam followers, means for moving said cam bars to force said die plate out of engagement with said restraining means and for carrying said die plate to a second position whereat the interaction of said restraining means and cam bars forces a second of said dies into engagement with said workpiece.

13. In an indexing apparatus for placing a die in working engagement with a workpiece, a die plate having a pair of dies mounted therein, cam followers secured to two opposite surfaces of said die plate, a restraining means for engaging said die plate to restrict vertical downward movement while said die plate and a first of said dies are in engagement with said workpiece, a first limit means for limiting the vertically upward movement of said die plate, a pair of cam bars having cam surfaces thereon for engaging said cam followers to guide said plate to and from engagement with said workpiece, said cam bars having recesses formed therein, power means for moving said cam bars in the vertical direction whereby said cam surfaces engage said followers and force the die plate out of engagement with said restraining means and first limit means, detents on said die plate adapted to engage said recesses in said cam bars to facilitate simultaneous unidirectional vertical movement of said die plate and said cam b ars, a second limit means for stopping the vertical downward movement of said die plate whereby said detents disengage said recesses and continued vertical movement of said cam bars cams the die plate into engagement with said restraining means to place a second of said dies into engagement with said workpieces.

14. In a fabricating machine for forming a workpiece, means for clamping the workpiece, means for restraining the clamping means to limit the clamping force applied to the workpiece, a forming tool, means actuated by the clamping means for advancing the tool into engagement with the clamped workpiece, means actuated by the advancing means moving the tool into engagement with the workpiece for interrupting the operation of the advancing means, and means rendered effective upon said interruption for overriding the restraining means so that the clamping means applies an unrestrained clamping force on the workpiece.

References Cited in the file of this patent UNITED STATES PATENTS 1,153,287 Candee Sept. 14, 1915 2,176,188 Poole et a1. Oct. 17, 1939 2,622,652 Conroy et a1. Dec. 23, 1952 2,766,825 P ater et a1. Oct. 16, 1956 

1. IN A FABRICATING MACHINE, A CLAMP, MEANS FOR ACTUATING SAID CLAMP TO GRIP A WORKPIECE, MEANS FOR OPPOSING SAID ACTUATING MEANS, A FABRICATING TOOL MOUNTED FOR MOVEMENT TOWARD A WORKPIECE GRIPPED BY SAID CLAMP, MEANS FOR MOVING SAID FABRICATING TOOL, AND MEANS OPERATED BY THE MOVEMENT OF SAID FABRICATING TOOL FOR RENDERING SAID OPPOSING MEANS INEFFECTIVE. 